Method and apparatus for cutting ferrous metal bar stock



April 3, 1951 2,547,191

L. w. YOUNG METHOD AND APPARATUSFOR cu'mmc FERROUS METAL BAR swocx Original Filed Now. 7, 1939 ELECTRICAL (VA/TRGL M2 90 H Wm... I 96 INVENTOR LLOY D w. YOUNG av L5,

ATTORNEY Patented Apr. 3, 1951 UNITED. STATES ENT FFHCE METHOD AND APPARATUS FUR CUTTING FERROUS ItiE'l'LAL BAR STOCK Lloyd W. Young, Elizabeth, N. 3., assignor to The Linde Air Products Company, a corporation of Ohio 13 Claims. l

The invention relates to the art of thermochemically cutting metals and more particularly to a method of rapidlv and efilciently cutting ferrous metal bar stock such as round or rectangular steel billets by means of gas-cutting blowpipes and to novel apparatus for practicing such method.

This application is a division of my copending application Serial No. 393,188, filed November 7, 1939, now abandoned.

Gas-cutting bloc "pipes, particularly those of the oxyacetylene type, provide an efficient means for cutting metal stock and in steel mills it has been proposed to use such means for removing scrap ends from billets or blooms, and for cutting heavy rounds or other shapes to predetermined lengths. In such application the blowpipe may be manually guided across the Work during the utting operation, or it may be caused to traverse the work by means of a suitable apparatus either automatically or semi-automatically controlled.

Prior apparatus adapted for severing round bars and comprising a gas-cutting blowpipe and means automatically or semi-automatically controlled to impart arcuate motion to said blow pipe across the bar, in general, have relied on a method of cutting in which the position of the blowpipe, with respect to the vertical axis of the work, remains substantially parallel as the blowpipe traverses the work. In cutting operations employing such a method, it is desirable to de crease the rate at which the blowpipe traverses the work as the thickness of the work increases, in order to compensate for the difference in degree of oxidation and cutting action which occurs between the gases at the upper or entrant portion of the kerf and those at the lower or emergent portion and which causes the bottom of the kerf to proceed at a slower rate than the top.

According to the invention the time required for making a cut is substantially reduced by employing more than one blcwpipe simultaneously, for example, two blowpipes may be employed for starting the cut at each lateral edge of the body. The movement of the two blowpipes toward each other from each edge is so controlled that when the blowpipes approach each other near the center of the body, one of the blowpipes is caused to stop cutting and reverse its movement and the other blowpipe completes the kerf.

A principal object of the present invention is to provide a method of and an appartus for decreasing the time requiredfor thermochemically 2 servering ferrous bodies of similar width and thickness.

Other objects of the invention are to provide a method of thermochemically severing metal bars, and the like, whereby the cutting action is advanced at the most efficient rate in each portion of the keri; to provide a method whereby a plurality of blowpipes may operate simultaneously for producing a single kerf to provide apparatus adapted for practicing such method;

be automatically or semi-automatically controlled.

The manner in which this invention attains these and other objects will be apparent from the following description and the accompanying drawing in which:

Figure 1 is a front elevational View partly in section of a preferred embodiment of the invention; and

Figure 2 is a horizontal section taken along line 22 of Figure 1.

The present invention is based on a method of blowpipe cutting which comprises heating a portion of the metal stock to its ignition temperature, directing a jet of oxidizing gas onto said heated portion to start a kerf therethrough, progressively moving said jet across the stock, and continuously changing the angle at which said jet strikes the stock during such movement.

In the preferred embodiment of the method and apparatus described herein two cutting units are employed, each propelled during the cutting operation in a common plane, but in opposite directions, toward the vertical axis of the work. In order to remove completely the metal from the center of the out, one of the cutting units is carried past the vertical axis. To accomplish this, a reversing mechanism is provided which is adapted to reverse the direction of one cutting unit at a predetermined point in its line of travel. Thus, one of the cutting units travels almost to the vertical axis of the work, and then its direction of travel is reversed, While the other cutting unit is carried past the vertical axis to com- I plete the out.

The invention herein described is particularly metal bodies, particularly 3 adapted for cutting hot billets, the heat of which is sufficient to ignite the preheating and cutting gases without external means. however, a pilot frame may readily be aiiixed to the apparatus so that the gases will automatically igni' when they are brought into contact with said flame.

Furthermore, the apparatus ha been described in connection with the cutting of substantially round billets or bars but it can be seen that the invention is not so limited and may readily be adapted to the cutting of other billet or bar shapes.

Cutting hot billets with two simultaneously operated blowpipes provides further advantages. For example, when cutting hot round billets with one blowpipe, slag will be found to accumuuate on the underside during the last half of the cut. This is because the billet is cylindrical in shape and the underside curves upward on the led of the cut. This upward curvature will cause the molten slag to flow back over the lower edge of the kerf. Such accumulation oi slag on either end of a billet will interfere with the proper fur ther working of the billet. Very little slag has been found to accumulate on the first half of the out due to the downward slope. Therefore, by using two blowpipes and starting the cuts di ametrically opposite each other, each cut 'vVlil. progress toward the center of the billet and the slag accumulation on the bottom will be negligible.

An embodiment of apparatus, according to the invention, adapted particularly for cutting bars and billets of similar width and thickness such as round, polygonal or square bars supported in the diamond position, is shown in the drawing positioned to cut a round bar W of substantially the largest diameter to be cut. At W is indicated in broken lines relatively one of the smallest round or square bars that can be cut by the apparatus.

The billets W may be supported horizontally by any suitable means. As shown, the billet W is carried by the rolls R of a conveyor which may be of the customary type employed in steel mills in which every other roll is motor driven. A V-block 6U vertically straddles the billet W and serves as a centralizing or aligning device for two blowpipes B and B. It often happens that the billets are not sufiiciently straight to cause them to come to rest with their axis directly over the center line of the conveyor, and in such case the V-block 66 will align the blowpipes with the billet irrespective of the position of the billet on the roll R. A tubular stem Bl secured to the center of the V-block 66 extends upward and is slidably mounted within a sleeve $3. The upper end of a spring 63 which surrounds the middle portion of the sleeve 82 rests against a collar 64 secured to the sleeve. The lower end of the spring 63 acts against projections 65 of the stem 6| which projections extend through longitudinal slots 66 in the sleeve 62. It will be seen that the downward force of spring 63 will act to hold the V-block firmly in contact with the surface of the billet W. The upper end of sleeve 62 is provided with diametrically opposite ears 61 and $1 to which are pivotally secured two blowpipe supporting arms 68 and 63. The pivot points 23 and 24 for the blowpipe arms 58 and 68 are located a substantial distance on either side of the center line of the sleeve 62. This offset is provided to improve the operation of the unit when the two blowpipes approach each other at the completion of a cut. A pair of blowpipe holders 69 and 59 are adjustably mounted in pivots It and ill at the lower ends of blowpipe supporting arms 68 and 88. Since both blowpipe holders are alike, only one will be described. Within the holder (id is disposed an inner sleeve ii that surrounds the blowpipe B and which is held in position in the sleeve H by a clamp l2. To the sleeve '1! is secured an annular worm gear 13 that meshes with a worm M secured to the trans? verse stem of a handwheel l6 rotatably supported by a bearing projection 15 of the blowpipe holder 69. Thus, the rotation of the handwheel '56 will rotate the worm Hi and turn the gear 13, sleeve H, and blowpipe B.

The cutting nozzle N is bent downwardly at an angle to the center line of the blowpipe. The nozzle is so formed that when the two cuts meet in the center of the billet, the cutting nozzles can approach one another more closely so that the uncut portion 25 that tends to remain in the middle of the work is reduced to a minimum. This uncut portion can be removed as will be hereinafter described. Since the cutting nozzles are bent, the means for rotating the blowpipe just described is employed for adjusting the position of the nozzle after it is clamped to the end of the blowpipe. It is desirable that the two cutting jets should lie in a common plane perpendicular to the longitudinal centerline of the billet, otherwise there may be an objectionable nick produced when the two cuts meet in the center of the billet. By turning the handwheel 76 minute radial adjustments of the cutting jets can easily be made even while the cutting operation is in progress. No lateral adjustment of the blowpipes is provided since there should not be an occasion to alter the relation between the blowpipe nozzle and the work once the proper setting has been established.

A small knurled roller Ti is provided to roll in contact with the surface of the billet W to maintain a uniform relation between the cutting nozzle N and the work surface. The roller 11 is mounted at the end of an arm "l8 that extends downwardly from the blowpipe holder 69. A similar roller ll and arm '58 are provided for the blowpipe B. Instead of a roller a skid could be employed provided that the radial center of the skid is no further away from the work surface than the axis of the roller which should be relatively small. Two inwardly directed projections is and is are provided on the blowpipe arms 68 and 58', respectively, and which are positioned to contact one another at the finish of the cut, i. e., projection 19 is disposed so that its contact with projection E9 will prevent the cutting nozzles N and N from coming in contact with each other at the finish of the cut.

To the upper end of the sleeve 52 is secured a square rack 80 having teeth along one side which mesh with a pinion 8i driven by an electric motor Mi through a variable-speed drive 82- and a wormear speed-reduction unit 83. The rack 83 extends vertically and. is positioned to one side of the center line of the sleeve 62 which oifset is to improve the balance of the mechanism which swings about the axial center of the pinion 85. A guide or enclosure 8 surrounds and slidably supports the rack SH and is pivotally mounted on one side thereof on the horizontal shaft of the reduction unit 83. The guide 8d permits free vertical movement of the rack 89 when it is moved by the pinion 3| and since the guide 84 is pivoted about shaft 85 the entire structure suspended on the rack is free to swing from side to side through a limited arc and thereby can readily align itself with the billet irrespective of the exact position of the billet on the roll table.

The pinion 8! is keyed to the shaft 85. The motor Mi, variable-speedreducer 32, and wormgear drive 83 are mounted together upon the top surface of a carriage {it which may comprise a rectangular frame and an upper deck or platform having an opening through which the rack 89 passes freely. The carriage is mounted on four flanged wheels 37 and 81'. The wheels 81 and 8? roll upon transverse rails 88 mounted longitudinally upon I-beams 89. To drive the carriage along the rails a motor M2 and a wormgear speed reducer 83 are provided. The reducer drives the wheels 3'! through a chain 9| meshing with a sprocket Q2 on the reducer and a sprocket 93 secured to an axle 95 that connects the left-hand wheels iii. The I-beams as may be supported in any suitable manner such, for example, as by and frames having lower ends secured to the floor. Flexible gas supply and electric conduits 35 are provided leading from a source of gas supply and electricity to a control box 86 mounted at the right-hand end of the carriage 85 wherein suitable electricaily-operated valves control the preheating gas and cutting oxygen. From box 5'5, three hoses, such as hoses 97, conduct the preheating gases and cutting oxygen to a pair of connection blocks 93 and 98' carried by extensions of the arms 58 and 68. From connection blocks 53 and Q8, fiexible metallic tubes, such as tubes 99', conduct the gases to the upper ends of the blowpipe B and B. The hoses and tubes for the left-hand block 98 are not shown in order to simplify the drawing.

Means for automatically controlling the operations of the apparatus shown in the drawing may also be provided. Thus a limit switch lei may be mounted on a vertically adjustable slide llll carried by the guide 84 and have its switch arm I82 operably engaging the upper portion of the rack 80. The position of the switch its is to be adjusted accord ng to the work diameter.

Means for controlling the rate of speed of the motor M! according to the height of the rack 39, and therefore, according to the thickness of the work being out while the rack 88 is moving up ward is also preferably provided. To this end there is provided in the speed reducer 82 a speed-regulating means which has a control shaft I 03. The shaft IE3 is turned by a chain 191i that meshes with a sprocket 495 secured to the shaft Hi3. One end of the chain tea is secured to a tension spring 19% attached to the carriage 86 and the other end of the chain is secured at iii! to the rim of a sprocket Hi8 secured to the shaft ofrthe reducer 83. When the rack 88 is raised the sprocket m8 rotates clockwise moving point is! to a horizontal position with respect to the axis of the sprocket I03.

During such movement the shaft I83 will be turned clockwise by the chain its and spring 5 E36, such movement being arranged to decrease gradually the output speed of the reducer 82. Further movement would gradually increase the speed. When the rack 8%) moves downward the reverse action occurs.

While the rack 89 is being lowered from th extreme upward position in which position the point Hi7 will be at the bottom of sprocket 38, the pinion 8i, sprocket H88, and the point it! will rotate in a counter-clockwise direction, and sprocket H35 will rotate in a clockwise direction thereby reducing the speed of rotation of the shaft 85. When the point IQ? has passed above the horizontal level of the axis of the shaft 85, the direction of rotation of the speed-control shaft I03 will be reversed and thereby the rate at which the rack is further lowered will gradually increase. In order to simplify the apparatus, the position of the point iii? of the sprocket IE8 has not been made adjustable according to the size of the billet. Therefore, when cutting the smaller diameter billets, the rate of upward travel would continue to decrease until the blowpipes pass the finishing position of the largest billet.

The diameters of sprockets E35 and Hill are chosen so that the rate at which the blowpipes are raised will be approximately in proportion to the thickness of the metal being out. When cutting bars of the larger diameters, the rack is raised higher and therefore the lifting speed is reduced to a greater extent. Because of the curvature of the work, the depth of the cut does not vary in a straight line proportion with the vertical movement of the rack whereas the variable speed mechanism, as above described, will decrease the speed of upward travel of the blowpipes substantially in direct proportion to their height. The discrepancy between the reduction of speed and the rate of increase of thick ness, however, is not especially disadvantageous because the cutting range with a given size nozzle and a given head pressure is relatively wide so that the cutting efficiency is substantially unaffected. Furthermore, the greatest change in thickness occurs at the beginning of the cut at which time the vertical movement is quickest.

A second limit switch its is secured on the top of the carriage t5 and located so that its switch arm H6 is positioned to engage the top of the stem SI when the rack to reaches its upper limiting position.

A third limit switch Hi is mounted on the side of the arm 53 and has a switch arm I l 2 connected by a rod MS with one arm of a bell crank i M pivoted on the arm 68 and having its other arm positioned to be contacted by the projection 19 when the arms 58 and $8 come together.

Two other limit switches H5 and H8 are also provided and are secured to the inside of the rearmost beam 89 in such a position that the switch arms iii and H8 make contact at the desired times with a cam H9 that depends from the underside of the carriage 255. The switches H5 and H3 control the motor M2 to position the carriage 86.

The operation of the machine shown is effected as follows: Assuming that the suspended lowpipe structure is in the raised position and several inches above the billet W, a billet is moved along the conveyor until the place to be cut is directly under the blowpipes B and B; To start the cutting operation, the motor M! is energized to rotate the pinion through the speed reducers 82 and 83 in a counter-clockwise direction so that the rack 6i] will move downward. The limit switch It!) is positioned vertically sothat its contact finger E92 will turn clockwise when the end of the rack 31 passes the switch. The arm i t2 closes an electrical circuit through a suitable electrical control to reverse the rotation of the motor M I, and also to turn on the preheating gases and cutting oxygen for each blowpipe. The preheating flames will heat portions on each side of the billet to an ignition temperature relatively quite rapidly if the billet is at a highly heated rolling temperature.

The electrical control is preferably arranged so that the preheating flames burn for a sumcient period of time to raise the surface to an ignition temperature before the oxygen stream is applied and the motor Ml started. As the rack 80 moves upward the blowpipes B and B traverse the billet surface approach toward each other. The rate of movement is gradually reduced during the cutting so that the blowpipes will move at a slower rate when cutting the thickest part of the billet. When the blowpipes approach each other the projection is will contact with the projection it and press against the downwardly extending arm of the bell crank i i l which will operate the limit switch I i l and close an electric c' suit that operates the motor control to stop the motor ME, and turn off the gases flowing to the blowpipe B and start the motor M2 in operation. Operation of the motor M2 will cause the carriage 86 to move toward the right. As the carriage es moves, the V block will remain in contact with the surface of the billet and the suspended structure will be tilted sufiioiently to cause the blowp-ipe B to out completely through the remaining metal 2% at the center of the billet. The carriage 8B continues moving toward the right until the arm N3 of the limit switch li contacts with the cam lit. The movement or" the arm HS closes an electric circuit that operates suitable relays and the motor control which will reverse the direction of rotation of the motor M2; stop the flow of gases to the blow inc 3 and start the motor M! to operate in a c eion that will turn the sprocket Si clockwise. carriage 86 continues moving to the left until the arm ill of the limit switch H5 contacts with the cam H9. The switch H5 then operates the motor control to stop the motor M2. lhe motor lvli continues to operate until the raol: has been raised a sufficient distance to cause the upper end of the stem 6% to contact the arm i it of the limit switch its, the operation of which causes the motor control to stop the motor Mi. When the blowpipe supporting mechanism is raised away from the billet, the operator controlling the roll table then causes the billet to continue along the roll table.

When square billets are cut, the rollers R preferably shaped to support the billets in the diamond position with a longitudinal corner upward. lhe V-block 59 then preferably engages only the two outer corners to permit angular swinging of the blowpipe support. The blowp-ipes will start cutting at the outer corners and move along the two upper sides toward. the upper corner, the operation of the apparatus being substantially the same as when cutting round stock.

What is claimed is:

1. A method of cutting elongated metal stock which comprises simultaneously directing at least two streams of oxidizing gas generally downwardly against surface portions on opposite sides of said stock to form kerfs therethrough, the metal to which said streams are applied being at an ignition temperature; progressively advancing said streams at substantially the same rate toward each other in a plane transverse to the longitudinal axis of said stock; and during the cutting, changing the angular relation between the axes of said streams to cause said streams to converge downwardly by moving said streams about pivots in said plane over the stool: on opposite sides thereof, while maintaining the degree of such angular relation less than a stra ht angle; interrupting the advance of and simultaneously shut.-

ting off one of said streams; continuing the ad Vance of the other of said streams until the lzerf produced thereby meets the herf made by the stream which was interrupted at the bottom of the stock; and further advancing said other stream while decreasing the angle thereof with respect to the breast of the lzerf made by the stream which was interrupted until the lierfs meet at the top of the stock and thereby complete the severing thereof.

2. A method of cutting elongated metal stock which comprises simultaneously directing from respective orifices at least two streams of oxidizing gas generally downwardly against surface portions on opposite sides of said stock to form lreris therethrcugh, the metal to which the streams are applied bein at an ignition temperaturprogressively advancing said streams at substantially the same rate toward each other in a plane transverse to the longitudinal axis of said stock while maintaining the orifice of each stream spaced from the surface of the stock by a stock rider engaging the surface of said stock adjacent the cutting point of each stream respectively, and during the cutting, changing the angular relation between the axes of said streams to cause said streams to converge downwardly, by moving said streams about pivots in said plane over said stock and on opposite sides thereof, while maintaining the degree of such angular relation less than a straight angle; interrupting the advance of one of said streams in the course of said cutting in response to arrival of said stream at a position of predetermined spacing from each other; simultaneously automatically shutting off, in response to the same arrival of both of said streams at said position of predetermined spacing, that same one of said streams of which the advance was interrupted; continuing the advance of the other of said streams until the kerf produced thereby meets the kerf made by the stream which was interrupted at the bottom of the stock; and further advancing said other stream until the keris meet at the top of the stock and thereby complete the severing thereof.

3. A method of cutting metal stock which comprises simultaneously directing at least two streams of oxidizing gas against surface portions on opposite sides of said stock to form kerfs therethrough, the metal to which said streams are applied being at an ignition temperature; progressively advancing said streams toward each other in a plane transverse to the longitudinal axis of said stock; interrupting the advance of and simultaneously automatically shutting off one of said streams; continuing the advance of the other of said streams until the kerf produced thereby meets the kerf made by the stream which was interrupted at the bottom of the stock; continuing the advance of the other of said streams until the meeting point of said kerfs rises to the top of said stool: and cuts completely through the remaining metal at the center of the stock; and during the cutting, changing the angular relation between the axes of said streams to cause said streams to converge downwardly, by moving said streams about pivots in said plane over said stock and on opposite sides thereof, while maintaining the degree of such angular relation less than a straight angle.

4. a method of thermochemically cutting metal stock which com s simultaneously directing at least two streans of oxidizing gas against surface portions on opposite sides of said stock to form kerfs therethrough, the metal to which said streams are applied being at an ignition temperature; progressively advancing said streams toward each other in a plane transverse to the longitudinal axis of said stock until the kerfs produced by said streams substantially meet; and during the cutting, continuously changing the angular relation between the axes of said streams to cause said streams to converge downwardly,

by moving said streams about pivots in said plane over said stock and on opposite sides thereof, while maintaining the degree of such angular relation less than a right angle.

5. In apparatus for cutting elongated metal stock, said apparatus having a track extending transversely of and above said stock, and power actuated carriage means movable along said track, the improvement which comprises blowpipe mechanism depending from said carriage means including pivoted blowpipe supporting arms and blowpipes respectively mounted on said arms and adapted to direct streams of oxidizing gas against opposite edges of said stock, said arms each having means engaging the stock for maintaining said blowpipes at a predetermined distance from said stock, means for progressively advancing said arms toward each other with said blowpipes in downwardly converging relation including means for interrupting the advance of one of said arms at a predetermined point, means for automatically shutting ofi the oxidizing gas stream of said blowpipe at said point, means for continuing the advance of the other of said arms until the kerfs produced meet at the bottom of the stock, and means for further advancing said other arm until the kerfs meet at the top of the stock and complete the severing thereof.

6. In apparatus for operating upon opposite sides of elongated metal stock in which track is adapted to be disposed adjacent to the stock to be operated upon and a "carriage is mounted to travel along said track, the improvement which comprises a blowpipe carrier supported by and depending from said carriage, a pair of blow pipe supporting means pivotally mounted on and depending from said carrier, blowpipes carried by said blowpipe supporting means and directed thereby for applying gas jets against the sides of the stock, v-groove means depending from said blowpipe carrier adapted to engage portions of the surface of said stock for centering said carrier with respect to the so engaged portions, means for raising and lowering said blowpipe carrier, and means engaging said blowpipe supporting means for moving them about their pivotal mounting means to cause said blowpipes to move transversely with respect to the surface of said stock toward and away from each other.

7. In a blowpipe apparatus forcutting elongated metal stock, in which a track is adapted to be disposed in a plane above and parallel to the stock to be operated upon; and carriage means are mounted to travel along said track; the improvement which comprises blowpipe carrier arms pivotally supported by said carriage means and depending therefrom; blowpipes carried by said blowpipe carrier arms adapted to direct oxidieing gas streams simultaneously against surface portions on opposite sides of said stool: to prod-uce kerfs therein; means on said blowpipe carrier arms adapted to engage the surface of said stop-i: for maintaining said blowpipes at a predetermined distance from the surface of said stock; means for raising and lowering said b1owpipe carrier arms about their pivots on said carriage means; means for causing said blowpipe 10 carrier arms to move said blowpipes along the surface of said stock toward and away from each other in a plane transverse to the longitudinal axis of said stock; means on one of said arms adapted to engage an abutment moving with the other of said arms for interrupting the advance of one of said blowpipes at a predetermined point; means for automatically shutting off the oxidizing gas stream of said blowpipe at said point; and means for continuing the advance of the other of said blowpipes at least until the kerfs produced meet.

8. In a blowpipe apparatus for operating upon elongated metal stock having a track adapted to be disposed transversely of the stock to be operated upon; and a carriage movably mounted to travel along said track for supporting blowpipes for movement transversely of said stock the improvement which comprises; V-block means de-- pending from said carriage and arranged to on gage the surface of said stock for positioning said blowpipes with respect to the surface of said stock; a blowpipe carrier pivotally supported by said carriage; a pair of depending arms pivotally mounted on said carrier; blowpipe's mounted at the lower ends of said arms for applying gas streams against the sides of said stock; means for maintaining said blowpi-pes at a predetermined distance from the surface of said stock; and means for raising and lowering said blowpipe carrier to cause said blowpipes to move transversely of the surface of said stock toward and away from each other.

9. In a blowpipe apparatus for operating upon elongated metal stock, a blowpipe carrier; a pair of depending arms pivotali'y mounted on said carrier; the pivotal mountings of said arms being horizontally spaced apart and disposed on the sides of the carrier which are opposite their respective arms; blowpipes mounted at the lower ends of said arms for applying gas streams against the sides of said stock; and means for raising and lowering said blowpipe carrier to cause said blowpipes to move transversely of the length of said stock toward and away from each other.

10. In a blowpipe apparatus for operating upon elongated metal stock, a blowpipe carrier; a pair of depending arms pivotally mounted on ,said carrier; blowpipes mounted at the lower ends of said arms for applying gas streams against the sides of said stock; means for raising and lowering said blowpipe carrier; and means to cause said blowpipes to move transversely of the length of said stock toward and away from each other; said blowpipes being provided with nozzles having downwardly directed orifices arranged at an angle to the main axes of said blowpipes to alow said nozzles to closely approach each other.

11. In a blowpipe apparatus for cutting elonated metal stock, the combination of a frame having a track adapted to be disposed adjacent stock to be out; a carriage mounted to travel along said track; blowpipe carrier means pivotaliy supported by said carriage; a pair of blowpipes pivoted on said carrier means in depending relation and; directed for applying cutting gas streams against opposite sides of said stock to form coplanar kerfs therein, said carrier beswingable in the plane of said kerfs about its pivot, l -shaped means connected with said carrier means for movement therewith transversely of said stool; and adapted to engage portions of the surface or" said stock on opposite sides thereof for centering said carrier means with respect to the so engaged portions of the surface of said stool; to out; means for raising and lowering blow-pipe carrier means; and means for moving said blowpipes transversely with respect to the surface of said stool: toward and away from each other.

12. In a blowpipe apparatus for cutting elongated metal stock, blowpipe carrier means, olowpipes pivotally mounted on said blowpipe carrier means and directed for applying cutting gas streams against opposite sides of said stock to form coplanar kerfs therein; mechanism for advancing said blowpipes toward each other in a plane transverse to the longitudinal axis of said stock, said mechanism including cans for continuously changing the angular relation between said blowpipes during such transverse movem nt; said mechanism also including means for interrupting the advance of one of said blowpipes while continuing the advance of the other before the kerfs produced can meet.

13. A machine for cutting elongated metal stock, comprising in combination, a track extending transversely above said stock, a carriage movable along said track, a blowpipe, mechanism on said carriage for supporting and propelling said blowpipe, means for mounting said blowpipe mechanism on said carriage and cooperating with said blowpipe mechanism for maintaining said blowpipe in the plane of the projected cut at all times during the movement of the blowpipe, an abutment on said carriage and depending below the top of said stool; in position to contact with the side or" the body to be out, said blowpipe mechanism including a blowpipe holder moved into operative position to start a cut at the edge of the metal body when the abutment is against the side of the body, means for moving said biowpipe mechanism substantially in said plane toward said stock into operative position and away from said stock into inopera- 12 tive position, means responsive to arrival of said mechanism into said operative position for turn ing on the supply of at least one of the gases to said blowpipe, and means for actuating said blowpipe mechanism to advance said blowpipe to form a kerf in the stock.

LLOYD W. YOUNG.

assnannons orran The following references are of record in the filo of this patent:

UNITED STATES PATENTS Number Name Date 1,695,095 Bucknam May 12, 1914 1,585,893 Coberly May 25, 1926 1,687,9{11 Bishop Oct. 9, 1928 1,633,173 Royer -1 Jan. 8, 1929 1,825,006 Schmidt Q Sept. 29, 1931 1,361,923 Jones June 7, 1932 1,335,107 emwn' Nov. 1, 1932 1,921,388 SChZi'lldt Aug. 2, 1933 1,923,778 Douglass Aug. 22, 1933 2,017,430 Anderson Oct. 15, 1935 2,067,549 Sykes 1 Jan. 12, 1937 2,143,969 Eiggert, Jr. Jan. 17, 1939 2,184,562 Rockefeller Dec. 26, 1939 2,283,346 Bucknam et a1. May 19, 1942 2,3453% Anderson 1 Mar. 28, 1944 2,345,688 Smith Apr. 4, 1944 2,410,134: Stevenson et a1. 001129, 19 16 FOREIGN PATENTS Number Country Date 6,215 France July 13, 1906 (3d addition to $19,132) 438,940 Great Britain NOV. 25, 1935 568,934 Germany 1 Jan. 26, 1933 DTHEE REFERENCES The Welding Encyclopedia, 8th edition, 1932, pages 308 and 317-320. 

